Apologies if I am using the wrong terminology, hopefully my explanation will help clarify.
I am trying to fake volumetric shadows for a spotlight. I need to fake them instead of using the built-in option because I need to maintain a constant beam diameter coming out of the light fixture and at tight beam angles the spotlight needs to be physically outside of the fixture so shadows needs to be turned off.
The way I am going about faking the shadows is with a scene depth capture that is locked at the position of the spotlight and using the cone angle for its fov. This is then sent out to a material light function that is clipping the intensity of the spotlight based on the scene depth
Now the results of this look like this:
What’s strange is that the sides are not touching the ground and I have found that the depth pass is capturing the perpendicular distance to the scene capture and its not taking into account that even when looking at a flat plane the distance would be longer the further away from the center you go. So currently, the depth looking at a flat plane is one solid value/distance when what I need is for it to calculate the ray distance for each pixel so the scene depth would look more like a radial gradient out from the center.
Is this possible with the setup that I currently have? Is there another way I should be going about this? I have already tried this tutorial and it gives me the same results. I can’t use anything other than a spotlight so reclights are not an option. Let me know if I need to clarify anything or post more diagrams. Any insight is helpful thanks!